Özet:

Among the different agronomic techniques used to reduce the negative effects of salinity, external applications of stress modulators are considered as an efficient approach for salinity stress alleviation. An experiment was conducted as a factorial arrangement based on a complete randomized block design in 3 replications to evaluate the foliar application effects of different stress modulators on the physiological and biochemical responses of cotton cultivated in a saline condition. The involved factors included foliar application time (flowering and flowering+bolling stages) and 4 stress moderator types (control, Salicylic acid (SA), Glycine Betaine (GB), and Sodium Nitroprusside (SNP)). Application times had no significant impacts on the plant physiological attributes. Foliar application of SA further increased the activities of enzymatic or non-enzymatic antioxidants in cotton as compared to the other osmotic modulators. SA spraying enhanced the contents of Chlorophyll a (76.4%), Chlorophyll b (47.7%), carotenoids (73.3%), proline (90.8%), catalase (82.6%), superoxide dismutase (74.5%), and guaiacol peroxidase (98.1%) in comparison to the control treatment. Overall, The modulatory effectiveness of the enzymes in reducing salinity stress by augmenting their antioxidant activities could be classified as SA>GB>SNP.

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